go project - add a migration and rename the dockerfiles so that Go is the primary

go/internal/store/upload.go

@@ -0,0 +1,61 @@
+package store
+
+import (
+	"sync"
+	"time"
+)
+
+// uploadHistory tracks running total/count of upload durations for one device.
+type uploadHistory struct {
+	mu    sync.Mutex
+	total time.Duration
+	count int64
+}
+
+func (u *uploadHistory) add(d time.Duration) {
+	u.mu.Lock()
+	defer u.mu.Unlock()
+	u.total += d
+	u.count++
+}
+
+func (u *uploadHistory) average() time.Duration {
+	u.mu.Lock()
+	defer u.mu.Unlock()
+	if u.count == 0 {
+		return 0
+	}
+	// Truncating integer division — same idea as C# BigInteger total / count.
+	return u.total / time.Duration(u.count)
+}
+
+func (s *Store) uploadFor(id DeviceID) *uploadHistory {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	u, ok := s.uploads[id]
+	if !ok {
+		u = &uploadHistory{}
+		s.uploads[id] = u
+	}
+	return u
+}
+
+// AddUpload records an upload duration (nanoseconds as time.Duration) for deviceID.
+// sent_at from the API is intentionally ignored here; the HTTP layer still accepts it.
+func (s *Store) AddUpload(deviceID DeviceID, uploadTime time.Duration) {
+	s.uploadFor(deviceID).add(uploadTime)
+}
+
+// AverageUploadTime returns the mean upload duration for deviceID.
+// Formatting for the API (duration.String()) belongs at the HTTP edge.
+// Unknown / never-seen devices return 0.
+func (s *Store) AverageUploadTime(deviceID DeviceID) time.Duration {
+	s.mu.Lock()
+	u, ok := s.uploads[deviceID]
+	s.mu.Unlock()
+	if !ok {
+		return 0
+	}
+	return u.average()
+}